Too many questions to give detailed answers. Maybe try one or two in a single post next time. Here are brief responses...

atheism

No good reasons to believe. No evidence of any gods.

naturalism

Existence exists. (Duh.) 'Things' seem to exist within existence. (Universe.) These things appear to have their own natures, rather than being completely random. (Nature.) No good reasons to believe that anything exists 'outside' of Nature. No evidence of the supernatural.

evolution

Human chromosome #2.

Endogenous retro-viruses (ERVs).

Long-term E. Coli experiment showing evolution of completely new ability to eat citrate.

Obvious similarity of humans and other apes.

All life made of cells.

Zero evidence for any other origin story.

theism

No good reasons to believe. No evidence of any gods.

christian theism

No good reasons to believe. No evidence of Christian god.

No difference between Yahweh and Santa, except Santa is nicer.

Obvious mythological nature of stories in Bible.

Catholic church.

Dark Ages.

Crusades.

Witches.

Inquisitions.

Galileo.

No good evidence for historical Jesus.

the cosmological

Argument from Ignorance

Non Sequitur

Self-refuting: What caused god?

Special pleading

Occam's Razor

Big Bang

Quantum Mechanics

Unnecessary vastness and age of universe (Church of Last Thursday makes as much sense)

ontological

Argument from Ignorance

Non Sequitur

Self-refuting: It's easy to be the greatest when you exist. Now, for a god to be the greatest when he *doesn't* exist? *That's* much more impressive; certainly greater than a god who takes the easy path of being the greatest while existing. Therefore, god doesn't exist.

Absurd: I can't conceive of a greater BJ than one that's happening to me right now. Therefore I must be getting the *greatest ever* BJ right now.

moral

Argument from Ignorance

Non Sequitur

Self-refuting: What is the explanation for god's morals?

Special pleading

Evolution

Game Theory

design

Argument from Ignorance

Non Sequitur

Self-refuting: What designed god?

Special pleading

Evolution

The list goes on and on

fine tunning

Argument from Ignorance

Non Sequitur

Self-refuting: What tuned god's characteristics?

Special pleading

transcendental

Argument from Ignorance

Non Sequitur

Circular

Self-refuting: Presupposes logic. Then goes on to abuse it like a Catholic priest. Invalidates the logic it supposedly defends; if it can be used to prove the Bible, it can be used to prove anything. Therefore God is illogical, and so is the logic of TAG.

The history of the human development of logic is well-known. TAG is constructed with human logic, not God's logic. (And poorly constructed, at that.)

Transcendental Argument for the Non-existence of God

resurrection of christ

Argument from Ignorance

Non Sequitur

Obvious myth

Biology/medicine

No contemporary evidence

Hi, Epicdean,

I agree you've given quite a lot to cover in one post, so I'm going to be selective in order to go into a bit of depth - I'll try and pick the things that I have found most convincing in my transition from Catholic to atheist.

Theism and Atheism

The argument that I've found most convincing both for atheism and against theism is simply the fact that there is no unequivocal evidence for the existence of any gods. Theists may argue - and do argue - that you have to be willing to believe in order to see the evidence, but that is the same as saying you have to be truly intelligent to see the emperor's clothes! For almost every aspect of the world that theists invoke the hand of their god, there is a simpler, more elegant, naturalistic explanation. This being the case, the resort to god-of-the-gaps reasoning has become increasingly invalid. Why should we not suppose that things like the origins of the universe, and the nature of consciousness - two things theists love to claim as the work of their god - will one day yield to rigorous empirical investigation?

For the last few hundred years, scientific understanding of our world and what lies beyond it have pushed the idea of a god further and further onto the fringes of knowledge. At the same time humans have found that there are explanations for natural phenomena that don't require god's intervention, we have also failed to find any actual evidence - observable, testable evidence - for the presence of a divine being. If, indeed, there is a god of sorts hiding away in some undiscovered corner of the universe, is this really the kind of being to which we would consider paying homage?

What made me realise that I am indeed an atheist and not an agnostic is the fact that the existence or nonexistence of any gods has become utterly irrelevant to the way I lead my life - apart from the fact that I enjoy arguing the case for atheism! My morality is my own, my life is my own, my loyalties are to my friends and family (including our dogs and cats) and the purpose of my life is whatever I decide it to be - hopefully something that results in happiness for me and mine.

The Cosmological Argument and Fine Tuning

This one, I believe, rests on the notion that the universe had to have a cause, if it had a beginning, and that cause must necessarily have been a transcendent, timeless, intelligent being, aka: the Judeo-Christian god (or so the assumption usually goes).

I have seen several people attempt intricate philosophical gymnastics in the endeavour to explain why this argument is sound, but none of these attempts has ever been convincing. Even if the universe had to have a cause, as such, there is no reason the cause had to have been a disembodied mind. I believe the current concept favoured by astrophysicists is the idea of the quantum vacuum, but I don't understand that one well enough to explain it. What I do know is that a pre-existing chaotic collection of particles that gave rise to matter as we know it constitutes a much simpler explanation than the pre-existence of a creative intelligence. Theists can't legitimately claim, in the same argument no less, that everything that exists had to have a cause, except their god.

As for the argument from fine tuning, that one is just completely arse-backwards. It starts with the assumption that humans constitute an end in ourselves, that the universe was somehow made to accommodate us, rather than the fact that blind processes gave rise to life, which then evolved into various forms to fit the environment - it was never a case of the environment being somehow built or shaped to suit us. I love how theists who resort to this argument can then turn around and claim that atheists are arrogant...

The Resurrection of Christ

I am often amazed at the lack of historiographical awareness of the people who make this argument. The fact of the matter is that there are actually no surviving eye-witness accounts of the life, death or resurrection of Jesus. There is no clear-cut, convincing evidence that Jesus even existed as an actual historical person, rather than a legendary figure of the nature of King Arthur. There are also so many similarities between the Jesus myth and the prevailing mythologies within the Roman Empire in the first couple of centuries CE that it's hard to claim any originality for the stories attached to Jesus. Furthermore, the sources often claimed as corroborating evidence for the existence of Jesus as an actual person in fact contain nothing other than vague mentions of a person who may or may not have been the Jesus of the Gospels.

The Argument from Morality

This is definitely one of my favourites. Theists love to claim that atheists have no possible anchor for morality, and that in the absence of a god, anything and everything is permissible.

One of the best counterarguments to this is the fact that the majority of theists don't actually cite their god or their holy book as the source of their morality. If we take the example of Christians, how many of them seriously follow all the moral precepts laid out in the Bible? They don't - they pick and choose which moral teachings they think are sound, based on their own knowledge and experience. That's just what the rest of us do - only without reference to the Bible. 

Furthermore, there is ample evidence to suggest that morality is essentially a function of our nature as social animals. Other social animals, such as wolves and great apes, clearly have social mores - mutually understood modes of behaviour that contribute to the survival and harmonious functioning of the group. We humans might like to think that there is something special about our notion of morality, but it still has its basis in a shared understanding of what is acceptable and what is not acceptable behaviour towards our own kind.

Some Sources

There are several books I have found enlightening in my journey from belief to unbelief. I believe it was indeed The God Delusion that helped me realise I was an atheist, not merely agnostic. However, probably the best atheist book I have so far found is Atheism Explained: from folly to philosophy, by David Ramsay Steele. I believe it's available on Amazon. Unlike the works of Dawkins and Hitchens, it's not a polemic, but a polite, well-reasoned demolition of the arguments for the existence of the Judeo-Christian god.

Just wanted to pick some of my favorites:

Christian God:  Specifically the trinity.  If, as the doctrine states, they are NOT three separate entities, then Xtians believe that Jesus constantly prayed to one of his 'personalities.'  Also, one of his 'personalities' let him die.  All this does it make it seem like Christianity should be polytheistic (which it should in order to make sense) but that gets xtian's panties in a bunch.

Ontological argument for God:  I never trust a purely logical argument.  People seem to forget that logic, the study of reason, a mental development from evolution, should not be considered infallible.  If it were then there wouldn't be so much controversy within the field itself.  Alternatively, external and physical truths should be used to validate the internal truths discovered by logic.  The idea that logic alone can lead one to conclude that existence has to have some quality is so arrogant I consider it a delusion of grandeur.  People aren't important, and neither are the things we can think up.

I once heard the argument that if Christianity is true then Christians should kill themselves. The argument goes like this:

P1:Since Christians love maximally God (Mark 12:28-30), their most intense desire is to be as close to God as possible.

P2:In the present existence, Christians are not as close to God as possible.

P3:But if they die and go to heaven, then they will be as close to God as possible.

P4:Every person wants to satisfy his/hers most intense desire as soon as possible.

C1:Therefore, Christians should desire to die as soon as possible.

P5:Christians will die as soon as possible if they commit suicide as soon as possible.

P6:There is nothing inconsistent between being a Christian and committing suicide.

C2:Thus, Christians should commit suicide as soon as possible.

Most Christians will object to P6 but there's really no explicit interdiction of suicide in Christianity and I think the counter-arguments are rather weak.

If that doesn't work then hit them with this:

http://www.youtube.com/watch?v=MeSSwKffj9o

Reliability of the results.

Zero evidence for any of them.

Say, do I have any more takers? This has been some GREAT stuff thus far. Thanks again.

It occurs to me that the strongest argument many Christians often make is that if you are open to belief in their god, you'll see the evidence all around you. That is their strongest argument. Think about that for a second.

This is what Christopher Hitchens refers to as wish-thinking. Those who want to see the work of a god in the natural world or in coincidental occurrences will see it, or will claim it - they won't see evidence of evolution, geological movement, weather patterns, neurological processes - they'll see evidence of god.

These same people will deny the evidence of history or of science, if it tells against their belief. They'll accuse nonbelievers of the same kind of wish-thinking in which they themselves engage. But the use of empirical investigation, in both the natural and the social sciences, works to counteract any kind of wish-thinking. Conclusions are based on evidence, or withheld in the face of a lack of evidence.

The empirical approach to gaining knowledge and understanding is qualitatively very different to the religious approach. Most religions claim a monopoly on "the truth", but observation, experiment and reason - the tools of empirical investigation - are much better at approaching any truths that matter.

This pretty much

..is the one where theists claim - usually after asserting that belief is necessary to morality - that atheism naturally and logically leads to evil and atrocity. Their evidence for this? Hitler and Stalin.

The most obvious retort is that totalitarian regimes were just as irrational as religion, perhaps moreso. The leader of the state is set up as an object of worship, and it is the omnipresent eyes of the law, rather than a god, that pry into everyone's private life.

I have been reading God Is Not Great, by Christopher Hitchens, and in one chapter he makes a very good case for the similarity between religion and totalitarianism - indeed the fact that they probably spring from the same innate, irrational human impulses. Not to mention the fact that the Catholic church, in particular, went hand-in-glove with fascist regimes (it is with no sense of hyperbole that I refer to the current Pope as a fascist), and acquiesced - in the case of Pius XII, with great enthusiasm - to the Nazis. It's an eye-opening argument. 

I've enjoyed reading them both. Thanks for taking the time.

How do you know this?

Well,  what  I  am  saying  is  we  can't  pretend  to  know  every  single  detail  or  get  inside  the  mind  of  God  and  determine  why  he  did  this  or  why  he  did  that.  I  said  that  because  the  person  whom  I  was  responding  to  was  making  an  argument  that  goes  something  like  this  "A  Deity  wouldn't  have  created  a  universe  with  so much  uneccesarry  space".  And  my  point  was,  we  don't  know  why  God  would  have  created  the  universe  with  so  much  empty  space.  He  may  have  his  reasons.  That  was  my  point

 Well,  according  to  Big Bang  cosmology,  space,  matter, time,  and  energy  came  into  being  with  the  initial  Big Bang singularity  (all  nature  came  into  being).  So  before  the  big  bang,  there  was  no  space,  time, matter,  or  energy.  So  it  logically  follows  that  if  the  Big Bang  was  the  cause  of  nature,  then  whatever  caused  the  Big Bang  had  to  transcend  (or  exist  beyond)  space,  matter,  time,  and  energy.  The  problem  is,  instead  of  postulating  the  supernatural,  most  close minded  people  don't  want  to  even ENTERTAIN  the  thought  of  the  supernatural.  I  find  this  very  absurd.

Well,  my  argument  from morality  is  not  based  on  just  morality.  It  is  based  on  OBJECTIVE  morality.  The  argument  is  not  that  you  can't  leave  a morally  good  life  without  God.  The  argument  is  without  God,  morality  can't  be  objective.  Everything  becomes  subjective.  You  think  stealing  is  wrong.  But  the  next  man  may  think  stealing  is  right.  You  may  have  a  million  reasons  why  you  think  stealing  is  wrong.  But  the  next man  may  have  a  million  different  reasons  why  stealing  is  right.  So  who  are  you  to  tell  a  man  that  stealing  is  wrong,  if  he  thinks  it  is  right?  For  objective  morality,  we  need  a  foundation  that  is  beyond  our  own  morality.  And  that  is  God

Except that the study of nature has made discoveries that are useful to EVERYONE, and, as such, are hard to argue against.  Spirituality may work for some, but for as long as it has been around, it hasn't had the impact that modern science and technology have had on society.

Well,  science  can  only  study  the  natural.  It  cannot  study  the  supernatural.  You  cant  put  the  supernatural  in  a  test  tube.  Science  is  in  no  position  to  study  the  supernatural.  Science  has  no  choice  but  to  stop  at  the  Big Bang.  That  is  the  furthest  that  science  can  go  back.  It  can't  go  back  any  further  than  that  because  the  cause  of  the  Big  Bang  is  not  natural,  nor  can  it  be  natural.

Actually,  i  can  provide  relevant  information.  You  mention  the  "causal  chain".  There  are  only  three  different  types  of  causations.

1. An uncaused cause (God)

2. A "caused by others" cause (Leonardo Da Vinci was the cause of the painting of the Mona Lisa"

3. A "self cause" (a  person  causes himself to be born)

Those  are  the  only  causes  that  we  are  familiar  with.  We  can  quickly  cancel  out  #3,  because  it  is  absurd.  Nothing  can  be  the  cause  of  itself.  Out  of  nothing,  nothing  comes.  #3  can  be  quickly  disregarded  because  it  is  absurd.  What  about  #2,  we  are  very  aware  of  this  cause.  When  builders  build  a  house,  they  are  the  cause  of  the  house.  You  were  the  cause  of  your  parents  reproducing.  No  one  will  argue  with  the  possibility  of  #2.  Now  here  is  where  philosophy  comes  in.  There  CANNOT  be  an  actual  infinite  amount  of  causes.  This  is  because  an  actual  infinity  can  not  exist  in  reality.  I  will  ask  you  to  do  some  research  on  the  concept  of  "infinity".  It  is  a lot  of  ground  to  cover.  But  to  wrap  it  up,  we  know  that  since  there  cannot  be  an  infinite  amount  of  "caused  by  other"  causes,  that  there  had  to  be  at  least  one  uncaused  cause,  which  is  #1.

 Not  so.  According  to  Big Bang cosmology,  energy  itself  did  not  exist  prior  to  the  Big Bang.  The  Big  Bang  was  the  cause  of  everything  that  is  considered  natural.  That  is,  all  space,  matter,  time,  and  energy.  Before  the  BB,  none  of  that  stuff  existed.  There  was  literally  NOTHING.  And  out  of nothing, nothing  comes. 

 Well,  from  a  natural  perspective,  time  itself  had  a  beginning.  So  if  time  had  a  beginning,  then  it  logically  follows  that  existence  has  a  beginning,  since  everything  natural  exists  in  time.  Remember,  the  universe  is  everything  that  physically  exist,  and  everything  that  physically  exist  came  into  being  with  the  BB,  that  is  all  space,  time,  matter,  and  energy.  The  only  question  is,  what  gave  it  that  beginning.

Lol.

Scientific naturalism wins by default. Philosophical naturalism does not. Google it or something.

Scientific naturalism does not presuppose that nature is all there is. By definition, natural things are the only things that can be reliably observed and tested, so these are the only things worth discussing. It doesn't arbitrarily exclude any category from existence because, by definition, as long as you can reliably observe something, then that thing is natural. However, it does exclude these things from the realm of logic and science, but simply based on the premise that they cannot be described by logic and science, by definition.

Psh.

Anyone can die for their belief system as long as they have a strong enough conviction. Muslims fly planes into building for their God. Buddhist monks set themselves on fire.

Of course, people aren't willing to die for Santa Claus, but I think this is because virtually no one actually believes Santa Claus exists except children. If people did believe that Santa Claus existed, I have no doubt that crazy things would be done in his name.   

Well, don't stop there. Keep going with the syllogistic reasoning. How do you know the cause is an immaterial intelligence?

Okay, then, how do you know God never began to exist?

Jesus, why this straman? Always. What is so appealing about this strawman?

If you talk to virtually any atheist, the answer you'll get the most is that we don't know what caused the universe. Nobody actually believes that the universe spontaneously popped out of the theistic conception of nothingness. 

You clearly do not understand quantum mechanics. Don't profess to understand something that you do not understand.

Occam's razor or Ockham's razor. Not "Occkams razor."

Heck, nothing can study the supernatural. You can't put it into any kind of tube, and nothing is in a position to study the supernatural.  

Why not? 

I pick number 2 then, unless you're assuming that it must be another intelligence, in which case, I invoke number 4.

4. Caused by a determined, unintelligent, impartial natural process.

Well, I'm guilty of this too, as we all are, but once you're talking about what happened "before the Big Bang," most of the intuitive concepts that we take for granted breaks down. What's to say that terms like causality, time, etc. can even be coherently applied? It's very possible that they are merely characteristics of our current universe and are meaningless in any other context.

I disagree, so I'm going to challenge that accuracy of that statement. 

I don't think Big Bang cosmology claims that energy did not exit prior to the Big Bang. Do you have a source? Reference? Citation?